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      <a id="powoftwo"></a>
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        <h2>
          <span class="refentrytitle">powoftwo</span>
        </h2>
        <p>powoftwo — 
      Performs a  power-of-two calculation.
          </p>
      </div>
      <div class="refsect1">
        <a id="idp135548544"></a>
        <h2>Description</h2>
        <p>
      Performs a  power-of-two calculation.
    </p>
      </div>
      <div class="refsect1">
        <a id="idp135549808"></a>
        <h2>Syntax</h2>
        <pre class="synopsis"><span class="command"><strong>powoftwo</strong></span>(x)  (init-rate or control-rate args only)</pre>
      </div>
      <div class="refsect1">
        <a id="idp135551920"></a>
        <h2>Performance</h2>
        <p>
      <span class="emphasis"><em>powoftwo</em></span>() function returns 2<sup><span class="emphasis"><em>x</em></span></sup> and allows positive and negatives numbers as argument. The range of values admitted in <span class="emphasis"><em>powoftwo</em></span>() is -5 to +5 allowing a precision more fine than one cent in a range of ten octaves. If a greater range of values is required, use the slower opcode <a class="link" href="pow.html" title="pow"><em class="citetitle">pow</em></a>.
    </p>
        <p>
      These functions are fast, because they read values stored in tables. Also they are very useful when working with tuning ratios. They work at i- and k-rate.
    </p>
      </div>
      <div class="refsect1">
        <a id="idp135556448"></a>
        <h2>Examples</h2>
        <p>
      Here is an example of the powoftwo opcode. It uses the file <a class="ulink" href="examples/powoftwo.csd" target="_top"><em class="citetitle">powoftwo.csd</em></a>.
      </p>
        <div class="example">
          <a id="idp135558224"></a>
          <p class="title">
            <strong>Example 646. Example of the powoftwo opcode.</strong>
          </p>
          <div class="example-contents">
            <p>See the sections <a class="link" href="UsingRealTime.html" title="Real-Time Audio"><em class="citetitle">Real-time Audio</em></a> and <a class="link" href="CommandFlags.html" title="Csound command line"><em class="citetitle">Command Line Flags</em></a> for more information on using command line flags.</p>
            <pre class="programlisting">
<span class="csdtag">&lt;CsoundSynthesizer&gt;</span>
<span class="csdtag">&lt;CsOptions&gt;</span>
<span class="comment">; Select audio/midi flags here according to platform</span>
-odac     <span class="comment">;;;realtime audio out</span>
<span class="comment">;-iadc    ;;;uncomment -iadc if realtime audio input is needed too</span>
<span class="comment">; For Non-realtime ouput leave only the line below:</span>
<span class="comment">; -o poweroftwo.wav -W ;;; for file output any platform</span>
<span class="csdtag">&lt;/CsOptions&gt;</span>
<span class="csdtag">&lt;CsInstruments&gt;</span>

<span class="ohdr">sr</span> <span class="op">=</span> 44100
<span class="ohdr">ksmps</span> <span class="op">=</span> 32
<span class="ohdr">nchnls</span> <span class="op">=</span> 2
<span class="ohdr">0dbfs</span>  <span class="op">=</span> 1

<span class="oblock">instr</span> 1	<span class="comment">; bit reduction for Lo-Fi sound</span>

iBits	  <span class="op">=</span> p5						<span class="comment">;bit depth</span>
iQuantize <span class="op">=</span> <span class="opc">powoftwo</span>(iBits)				<span class="comment">;find number of discrete steps for this bit depth</span>
iQuantize <span class="op">=</span> iQuantize<span class="op">*</span>0.5				<span class="comment">;half the number of steps for each side of a bipolar signal</span>
<span class="opc">print</span>	  iQuantize
asig	  <span class="opc">soundin</span> "fox.wav"
asig	  <span class="op">=</span> <span class="opc">round</span>(asig <span class="op">*</span> iQuantize) <span class="op">/</span> iQuantize		<span class="comment">;quantize audio signal (bit reduce)</span>
	  <span class="opc">outs</span> asig, asig         

<span class="oblock">endin</span>
<span class="csdtag">&lt;/CsInstruments&gt;</span>
<span class="csdtag">&lt;CsScore&gt;</span>
<span class="comment">;        bits</span>
<span class="stamnt">i</span>1 0   3  16
<span class="stamnt">i</span>1 ^+3 .  12
<span class="stamnt">i</span>1 ^+3 .   8
<span class="stamnt">i</span>1 ^+3 .   4
<span class="stamnt">i</span>1 ^+3 .   2
<span class="stamnt">i</span>1 ^+3 .   1

<span class="stamnt">e</span>
<span class="csdtag">&lt;/CsScore&gt;</span>
<span class="csdtag">&lt;/CsoundSynthesizer&gt;</span>
</pre>
          </div>
        </div>
        <p><br class="example-break" />

      Its output should include a line like this:
      </p>
        <pre class="screen">
instr 1:  iQuantize = 32768.000
instr 1:  iQuantize = 2048.000
instr 1:  iQuantize = 128.000
instr 1:  iQuantize = 8.000
instr 1:  iQuantize = 2.000
instr 1:  iQuantize = 1.000
</pre>
        <p>
    </p>
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      <div class="refsect1">
        <a id="idp135563536"></a>
        <h2>See Also</h2>
        <p>
      <a class="link" href="logbtwo.html" title="logbtwo"><em class="citetitle">logbtwo</em></a>, 
      <a class="link" href="pow.html" title="pow"><em class="citetitle">pow</em></a>
    </p>
      </div>
      <div class="refsect1">
        <a id="idp135566576"></a>
        <h2>Credits</h2>
        <p>
      </p>
        <table border="0" summary="Simple list" class="simplelist">
          <tr>
            <td>Author: Gabriel Maldonado</td>
          </tr>
          <tr>
            <td>Italy</td>
          </tr>
          <tr>
            <td>June 1998</td>
          </tr>
        </table>
        <p>
    </p>
        <p>
      </p>
        <table border="0" summary="Simple list" class="simplelist">
          <tr>
            <td>Author: John ffitch</td>
          </tr>
          <tr>
            <td>University of Bath, Codemist, Ltd.</td>
          </tr>
          <tr>
            <td>Bath, UK</td>
          </tr>
          <tr>
            <td>July 1999</td>
          </tr>
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        <p>
    </p>
        <p>New in Csound version 3.57</p>
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